Hey!
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One angle= 40°
Second angle = x°
Third angle= x°
Second and third angle will be equal as both the sides of triangle are equal.
Now, We know that sum of all angles in a triangle is 180°, so,
40+x+x=180
40+2x=180
2x=180-40
2x=140
x=140/2
x=70°
So Correct Option- (B) 70°
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Hope it helps...!!!
